What is wrong, terribly wrong, with wordles

I love wordles! They're so cool, like making artwork out of a big long text that I don't want to bother reading! I can see what's really important in a text by what's most common! And I get that in a flash!

I can't stand wordles. They're so mindless and dumbing down. Any good text will have a variety of vocabulary. frequency is misleading, texts are not just dumb bags of words.

These are extremely tendentious. I believe them both. But what I'll explain is what is problematic with them as data visualization.

What's a wordle? Also known as a tag cloud or word cloud, it's a graphic design method that takes a document, determines the frequencies of the unique words in that document, and mooshes the text of the words into an image, some vertical, the size of the word text in proportion to its frequency in the document. So from some document we get the dry list of individual word frequencies:

Wordle 127
word 35
words 30
cloud 28
students 22
clouds 22
Day 18
lessons 12
fused 12
adjectives 6
historical 5
classroom 5
even 4
see 4
...

This can be converted into a barchart:

which is the Zipf curve  of the document.

Now comes the cool graphic the wordle. instead of boring bars, make the word itself and its size tell you how important it is. Mushing them all together and letting the natural instinct of readability draw your eye to what's important:

It is certainly esthetically pleasing, a bit Mondrian, with a jazzy visual rhythm. The algorithm to lay out the words is clever in simplicity, and the resulting image allows some simple inference about a text.

But what is the point of a wordle and how successful is it for what ever points it might have?
If the point is that it is a piece of art, then I've made a case for it already. A new wordle for each new document is a bit derivative though, with too many barely distinguishable varieties. One here or there is great, but a number of them is numbing.

How is it as a data visualization? How well does it relate the data?

The ostensible purpose of a wordle is to show you the relative frequency of words in a document. What is actually done is to show you the obvious top two or three most frequent words. All other words are essentially ignored.

That may very well be the best part of the wordle, that it presents essential information (the two or three most frequent) in an esthetically pleasing manner. The size of a word pulls your eye towards it because it is easier to read, and if it is readable, there's no unreading it (it forces its meaning on you).

- the eye is encouraged to dance around. this may account for the esthetics, but it is an annoyance for comparison.
- Vertical presentation of a word almost guarantees that you can't read it.
- comparison of size is even more difficult than a pie chart. two words not even exactly next to each other are difficult to compare (the word length itself is not the frequency but it accounts for the relative noticeability.

So really the information that can be pulled out of a wordle is: the most frequent word (which does usually outweigh all others in most documents), the second and third most frequent, but you're not sure which is which, and maybe one or two in the top ten but maybe you missed some.

Under this analysis,  this is a Type V error in Fung's Visualization Trifecta Checkup, where the data and questions are well defined, but the visualization (the V) just isn't right.

So instead of complaining, what would be a better method, one that would actually address the stated purpose of showing relative frequencies?

The simplest (and least graphically pleasing) is the source list of stats: a text list, one word per line followed by its count in the document. Because numbers themselves are hard to judge easily in a list (but lengths are), maybe using a barchart sorted by frequency, and then maybe cut off at about 10 or so. The screen space taken up by the frequency list is about the same as the wordle image itself and allows extraction of a lot more information. All the information  is in this list, and it is all readable, and all comparisons can be made very easily. Surely there are frequency questions that can be asked that are not easily answered by the list, but what might be slightly difficult for the list is impossible for the wordle.

What this says is that wordles are really good at showing you the top couple of words in an esthetically pleasing manner; what it puts in your head is mostly 'X is the most common, and Y is maybe a little less common' and thats the extent of its specificity.

But if you want to know even minimally less vague comparisons, and more than 2 words, a wordle does not do it that well.

Or to put it more bluntly, a wordle is popular because it is beautiful, not true.

TL;DR: A wordle is estheticaly pleasing but is not even as good as a piechart for transmitting information.